1. Field of the Invention
The invention is in the general field of improved methods of pumping viscous hydrocarbons through a pipe, such as a well-bore or a pipeline.
2. General Background
The movement of heavy crudes through pipes is difficult because of their high viscosity and resulting low mobility. One method of improving the movement of these heavy crudes has included adding to the crude lighter hydrocarbons (e.g. kerosine distillate). This reduces the viscosity and thereby improves the mobility. This method has the disadvantage that is is expensive and the kerosine distillate is becoming difficult to obtain.
Another method of improving the movement of these heavy crudes is by heating them. This requires the installation of expensive heating equipment and thus is an expensive process.
The use of oil-in-water emulsions, which use surfactants to form the emulsion is known in the art.
I have found that the use of a small amount of a basic compound (e.g. NaOH) in conjunction with certain specific surfactants provides an improvement. The use of the basic compound reduces the amount of surfactant required and thereby reduces the cost. Furthermore, the use of the basic compound enables the use of such a small amount of surfactant that refining problems are reduced or eliminated.